In a speech to the Sydney Business Chamber on Tuesday, his first since assuming the role, Mr Hunt is expected to emphasise the susceptibility to extreme heat of people living in large cities.

Urban development pressures can lead to treeless streets that amplify the "heat island" effect on hot days.

"Extreme heat place[s] the most vulnerable people in our cities - including the very young and very old - at high risk, and contributes to a number of deaths each year," his speech notes say.

As well as decade-by-decade goals to develop urban canopies, the government will "look at building rooftops with green cover".

Environment Minister Greg Hunt.Credit:Alex Ellinghausen

Mr Hunt will warn that the public purse cannot fund the infrastructure needed to keep up with rapid growth in capital cities, and will point to flexible financial arrangements being considered by the government.

These include "value capture" - finance models that aim to capture the gain in land value that property owners enjoy when public infrastructure is built nearby.

Sunbathers enjoy a rooftop garden in Melbourne.Credit:Justin McManus

It can include property taxes, parking levies or giving property development rights to transport operators.

"One of the fairest ways to fund new infrastructure investment is for the beneficiaries of that infrastructure to contribute to the cost," Mr Hunt will say.

The government will also seek to increase the number of jobs in residential areas, to limit commute times.

Mr Hunt's speech notes praise the "20 minute city" model proposed in Melbourne where, through changed land-use mix, every suburb would be a short commute to jobs, schools, shops and leisure facilities.

He is expected to hail the emergence of the Greater Sydney Commission, the new organisation charged with overseeing planning and development across Sydney. It is led by the Prime Minister's wife Lucy Turnbull.

Mr Hunt will flag a potential expansion of that model to other cities, saying it shows how all levels of government can work together to "plan for how our cities will grow".